If you see steam coming out of the sides of a microwave while reheating food, it does not necessarily mean that harmful radiation is leaking out. Microwaves are designed to contain the microwave radiation within the microwave cavity, and there are safety measures in place to prevent radiation leakage.
The steam you observe is most likely the result of moisture present in the food being heated. Microwaves work by emitting electromagnetic waves (microwaves) that excite water molecules in the food, causing them to vibrate and generate heat. This process releases steam as the water molecules turn into vapor.
While the presence of steam is normal, it is essential to ensure that your microwave is in good working condition. If you suspect that your microwave is damaged or has issues with its door seal, it's best to have it inspected and repaired by a qualified technician. Microwave ovens are subject to safety regulations and must undergo testing to ensure they do not leak harmful levels of radiation under normal operating conditions.
To maintain safety, always use microwave-safe containers, follow the manufacturer's guidelines, and avoid using a microwave that shows signs of damage or malfunctions. It's also a good idea to keep some distance from the microwave when it's in operation to minimize exposure to any minor leaks that might occur, although this is typically not a significant concern with properly functioning microwave ovens.